Completion System

ABSTRACT

An expandable completion system and method of completing a well in which gravel packing of multiple completion zones is achieved by morphing a sleeve across a gravel packed annulus to secure it to a well bore wall by the use of fluid pressure to provide a zonal isolation barrier between two gravel packed zones in a wellbore. An embodiment provides gravel packing for multiple completion zones by circulation. A further embodiment allows selective isolation barriers to be created along the length of the completion string after the gravel has been pumped into the annulus.

BACKGROUND

The present invention relates to an apparatus and method for completinga well by securing a tubular within another tubular or borehole,creating a seal across an annulus in a well bore, and centralising oranchoring tubing within a wellbore. In particular, though notexclusively, the invention relates to morphing a sleeve across a gravelpacked annulus to secure it to a well bore wall by the use of fluidpressure to provide a zonal isolation barrier between two gravel packedzones in a wellbore.

In the exploration and production of oil and gas wells, sand productioncan have devastating effects as it will erode hardware; cause blockagesin the tubulars and surface equipment; and can create downhole cavitiesresulting in formation subsidence and casing collapse. Methods ofcompleting sand-prone formations have therefore been developed with themost widely adopted being gravel packing. A slurry of gravel is pumpedinto the annulus between a centralized screen and either perforatedcasing or open borehole. The fluid in the slurry is pumped into theformation or through the screen and back to surface leaving a gravelpack. The gravel pack acts as a granular filter with very highpermeability but prevents the formation sand from entering the wellbore.

Completing multiple zones is very difficult as the slurry requires to beinjected into the annulus between the packers used to isolate each zone.The slurry must entirely fill the annulus between the packers as anyvoid will promote sand production and risk formation subsidence andcasing collapse. The most reliable method of ensuring even distributionis achieved at the rat-hole where the slurry is pumped down a servicestring and returns up the annulus.

Packers are typically used to isolate one section of a downhole annulusfrom another section of the downhole annulus. The annulus may be betweentubular members, such as a liner, mandrel, production tubing and casingor between a tubular member, typically casing, and the wall of an openborehole. These packers are carried into the well on tubing and at thedesired location, elastomeric seals are urged radially outwards orelastomeric bladders are inflated to cross the annulus and create a sealwith the outer generally cylindrical structure i.e. another tubularmember or the borehole wall. These elastomers have disadvantages,particularly as they may be easily eroded.

As a result, metal seals have been developed, where a tubular metalmember is run in the well and at the desired location, an expander toolis run through the member. The expander tool typically has a forwardcone with a body whose diameter is sized to the generally cylindricalstructure so that the metal member is expanded to contact and sealagainst the cylindrical structure. These so-called expanded sleeves havean internal surface which, when expanded, is cylindrical and matches theprofile of the expander tool. These sleeves work well in creating anannular seal between tubular members but can have problems in sealingagainst the irregular surface of an open borehole.

The present applicants have developed a technology where a metal sleeveis forced radially outwardly by the use of fluid pressure actingdirectly on the sleeve. Sufficient hydraulic fluid pressure is appliedto move the sleeve radially outwards and cause the sleeve to morphitself onto the generally cylindrical structure. The sleeve undergoesplastic deformation and, if morphed to a generally cylindrical metalstructure, the metal structure will undergo elastic deformation toexpand by a small percentage as contact is made. When the pressure isreleased the metal structure returns to its original dimensions and willcreate a seal against the plastically deformed sleeve. During themorphing process, both the inner and outer surfaces of the sleeve willtake up the shape of the surface of the wall of the cylindricalstructure. This morphed isolation barrier is therefore ideally suitedfor creating a seal against an irregular borehole wall.

Such a morphed isolation barrier is disclosed in U.S. Pat. No.7,306,033, which is incorporated herein by reference. An application ofthe morphed isolation barrier for FRAC operations is disclosed inUS2012/0125619, which is incorporated herein by reference. Typically,the sleeve is mounted around a supporting tubular body, being sealed ateach end of the sleeve to create a chamber between the inner surface ofthe sleeve and the outer surface of the body. A port is arranged throughthe body so that fluid can be pumped into the chamber from thethroughbore of the body.

US 2004/0074642 to Schlumberger Technology Corporation discloses anexpandable completion system and method, by expanding a pair of spacedapart expandable sand screens in a well, the expandable sand screensconnected to one another by an unexpanded tubing section, and gravelpacking the portion of the well around the unexpanded tubing section.Zonal isolation is achieved by setting packers at the unexpanded tubularsection prior to gravel packing the annulus between the packer and eachsand screen, respectively. Gravel packing may also be done around theexpandable sand screen. This arrangement has the same disadvantage asthe prior art in that a gravel packing sub must be located at eachannulus between the sand screens or between a sand screen and a packerwith the potential result of uneven gravel packing. Additionally, it isdifficult to expand a sand screen reliably to ensure a desired mesh sizeis achieved when expansion is completed downhole.

It is therefore an object of the present invention to provide anexpandable completion system and method which obviates or mitigates oneor more disadvantages of the prior art.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided amethod of completing a well, comprising:

-   -   locating a sleeve member on the exterior of a tubular body and        sealing it thereto to create a chamber therebetween,    -   using the tubular body to connect two sand screens together in        an assembly;    -   running the assembly on a string into a wellbore and positioning        the sleeve member at a position between zones within a larger        diameter structure;    -   pumping fluid through a port in the tubular body to access the        chamber;    -   causing the sleeve member to move radially outwardly to morph        against an inner surface of the larger diameter structure; and    -   providing a gravel mixture through at least one portion of the        assembly to locate between the tubular body and the large        diameter structure.

In this way, gravel packing can advantageously be provided to enhancethe effectiveness of the isolation barrier created by the morphed sleevemember.

The method may include locating multiple assemblies on the string andundertaking the morphing of the sleeve and the provision of a gravelmixture at any desired locations where an isolation barrier is required.In this way, multiple zone completion is achieved.

The large diameter structure may be an open hole borehole, a boreholelined with a casing or liner string which may be cemented in placedownhole.

Preferably, pumping fluid through a port in the tubular body to accessthe chamber involves pumping fluid through multiple ports in the tubularbody to access the chamber. This provides a faster morphing of thesleeve.

Preferably, the method includes the step of rupturing a disc at a valvein the port to allow fluid to enter the chamber when the pressurereaches a desired value. This allows selective and controlled activationof the morphing process.

The method may include the steps of running in an activation fluiddelivery tool, creating a temporary seal above and below the port andinjecting fluid from the tool into the chamber via the port. Such anarrangement allows selective operation of the sleeve member.

The method may include the step of inserting an inner completion stringinto the string and isolating the sand screens by sealing between theinner completion string and the tubular body. In this way, productioncan be controlled from each zone.

In an embodiment, the method of providing a gravel mixture may includepumping gravel slurry through the string to exit at an end of thetubular body and circulate up an annulus between the assembly and thelarger diameter structure. This enables gravel packing to be achieved bycirculation in the wellbore.

The pumping of fluid through a port in the tubular body to access thechamber and cause the sleeve member to move radially outwardly may occurafter the gravel slurry is pumped through the string into the annulus.The sleeve may move radially outwardly to crush the gravel and morphagainst the inner surface of the large diameter structure. In such anarrangement, the gravel packing is achieved by circulation in thewellbore with the isolation barrier being operated after the gravel isin place.

In an embodiment, the method may comprise causing the sleeve member tomove radially outwardly to morph against an inner surface of the largerdiameter structure before providing a gravel mixture by pumping gravelslurry through at least one shunt tubular component of the assembly toan exit located between the morphed sleeve member and an end of thetubular body such that the gravel slurry circulates around an annulusbetween the assembly and the larger diameter structure. This enablesgravel packing to be achieved by direct provision of the gravel slurryinto the annulus of the wellbore after a morphed annular barrier is inplace and enables the continued supply of gravel slurry regardless ofcirculation in the annulus.

The gravel slurry may be operable to set when packed in the annulus asrequired. By providing gravel slurry which can set, an effective gravelpacked annular barrier is formed below the morphed sleeve annularbarrier thus securing the assembly effectively.

The at least one shunt tubular may be provided with a valve. Provisionof a valve in a shunt tubular enables the effective sealing of the shunttubular after the gravel is packed and set thus ensuring a completeannular barrier is formed around the assembly.

In an embodiment, the method of providing a gravel mixture may includepumping gravel slurry through the string to exit at an end of thetubular body and circulate up an annulus between the assembly and thelarger diameter structure and pumping gravel slurry through at least oneshunt tubular component of the assembly to an exit located between thesleeve member and an end of the tubular body such that the gravel slurrycirculates around an annulus between the assembly and the largerdiameter structure. This enables gravel packing to be achieved bycirculation and direct provision in the annulus in the wellbore.

The pumping of fluid through a port in the tubular body to access thechamber and cause the sleeve member to move radially outwardly may occurafter the gravel slurry is pumped into the annulus. The sleeve may moveradially outwardly to crush the gravel and morph against the innersurface of the large diameter structure. In such an arrangement, theisolation barrier is operated after the gravel is in place.

According to a second aspect of the present invention there is providedan expandable completion system, comprising:

an assembly comprising two sand screens connected via a tubular body,the assembly including connections for location in a tubular string tobe run in and secured within a larger diameter generally cylindricalstructure;

wherein a sleeve member is positioned on the exterior of the tubularbody, to create a chamber therebetween;

the tubular body including a port to permit the flow of fluid into thechamber to cause the sleeve member to move outwardly and morph againstan inner surface of the larger diameter structure wherein the assemblyis operable to provide a gravel slurry into an annulus between theassembly and the larger diameter structure.

In this way, the completion system is easily assembled and run in to awellbore. The screens are not expandable and thus the mesh size can befixed.

The sleeve member may have a first end which is affixed and sealed tothe tubular body and a second end which includes a sliding seal topermit longitudinal movement of the second end over the tubular body. Inthis way, as the sleeve is morphed, longitudinal contraction of thesleeve member occurs which reduces the thinning of the sleeve memberduring morphing.

The large diameter structure may be an open hole borehole, a boreholelined with a casing or liner string which may be cemented in placedownhole.

Preferably, there is a plurality of ports arranged through the tubularbody. In this way, rapid morphing of the sleeve member can be achieved.The ports may be arranged circumferentially around the body. The portsmay be arranged longitudinally along the body.

The port may include a barrier. In this way, fluid is prevented fromentering the chamber until activation is required. The barrier may be arupture disc which allows fluid to flow through the port at apredetermined fluid pressure. Alternatively the barrier may be a valve.Preferably the valve is a one-way check valve. In this way, fluid isprevented from exiting the chamber.

The sand screens may be of any configuration known to those skilled inthe art. In this way standard sand screens can be used. The sand screenmay be a slotted liner or any other arrangement used to filterproduction fluid entering the tubular string.

Preferably, the system includes a plurality of assemblies. Theassemblies may be separated by a tubular body, wherein a sleeve memberis positioned on the exterior of the tubular body, to create a chambertherebetween; the tubular body including a port to permit the flow offluid into the chamber to cause the sleeve member to move outwardly andmorph against an inner surface of the larger diameter structure. In thisway a multiple zone completion system is formed.

In an embodiment, the assembly comprises a string exit at an end. Gravelslurry may be pumped through the string to exit at the string exit. Suchan assembly enables the gravel slurry to be output at the string end andcirculate up an annulus between the assembly and the larger diameterstructure due to circulation in the wellbore. The gravel packing may besupplied such that on actuation the sleeve member is operable to moveoutwardly to crush gravel and morph against an inner surface of thelarger diameter.

In an embodiment, the assembly comprises at least one shunt tubularhaving at least one shunt exit located between the sleeve member and anend of the tubular body. Gravel slurry may be pumped through the shunttubular such that it exits at the shunt exit and circulates around anannulus between the assembly and the larger diameter structure. Thisassembly gravel packing to be achieved by direct provision of the gravelslurry into the annulus of the wellbore. The provision of gravel slurrythrough the shunt tubular may occur after the sleeve member is actuatedsuch that a morphed annular barrier is in place and such an assemblyenables the continued supply of gravel slurry regardless of circulationin the annulus.

The at least one shunt tubular may be provided with a valve. Provisionof a valve in a shunt tubular enables the effective sealing of the shunttubular after the gravel is packed and set thus ensuring a completeannular barrier is formed around the assembly.

In an embodiment, the assembly may comprise string exit at an end and atleast one shunt tubular having at least one shunt exit located betweenthe sleeve member and an end of the tubular body. Such an arrangementenables gravel slurry to be provided through the string exit and throughthe shunt tubular to achieve an annular gravel pack in an expedientmanner.

In the description that follows, the drawings are not necessarily toscale. Certain features of the invention may be shown exaggerated inscale or in somewhat schematic form, and some details of conventionalelements may not be shown in the interest of clarity and conciseness. Itis to be fully recognized that the different teachings of theembodiments discussed below may be employed separately or in anysuitable combination to produce the desired results.

Accordingly, the drawings and descriptions are to be regarded asillustrative in nature, and not as restrictive. Furthermore, theterminology and phraseology used herein is solely used for descriptivepurposes and should not be construed as limiting in scope. Language suchas “including,” “comprising,” “having,” “containing,” or “involving,”and variations thereof, is intended to be broad and encompass thesubject matter listed thereafter, equivalents, and additional subjectmatter not recited, and is not intended to exclude other additives,components, integers or steps. Likewise, the term “comprising” isconsidered synonymous with the terms “including” or “containing” forapplicable legal purposes.

All numerical values in this disclosure are understood as being modifiedby “about”. All singular forms of elements, or any other componentsdescribed herein including (without limitations) components of theapparatus are understood to include plural forms thereof.

The terms ‘seal’ and ‘isolation’ are used with the recognition that someleakage may occur and that such leakage may be acceptable. Thus, someembodiments of the present invention may allow for leakage withoutdeparting from the scope of the invention and systems that provide forsuch leakage fall within the scope of the present invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Embodiments of the present invention will now be described, by way ofexample only, with reference to the accompanying drawings of which:

FIGS. 1 a-1 c are schematic illustrations of a sequence for completing awell; FIG. 1 a is a cross-sectional view of an assembly according to thepresent invention located in a wellbore; FIG. 1 b shows gravel beingpumped into the wellbore and circulated therethrough; and FIG. 1 c is across-sectional view of the assembly of FIG. 1 a with a morphed sleevehaving crushed the gravel and sealed against the wall of the wellbore;and

FIGS. 2 a-2 c are schematic illustrations of a sequence for setting twosleeve members in an open borehole during a completion according to anembodiment of the present invention; FIG. 2 a is a cross-sectional viewof a tubular string with two assemblies according to the presentinvention and the deployment of gravel; FIG. 2 b shows the tubularstring in the borehole with an activation fluid delivery tool insertedtherein; and FIG. 2 c is a cross-sectional view of the tubular stringwith morphed sleeves and an inner completion string.

FIGS. 3 a-3 c are schematic illustrations of a sequence for setting asleeve member in an open borehole during a completion according to anembodiment of the present invention. FIG. 3 a is a cross-sectional viewof an assembly according to the present invention located in a wellbore;FIG. 3 b is a cross-sectional view of the assembly of FIG. 3 a with amorphed sleeve sealed against the wall of the wellbore; and FIG. 3 cshows gravel being pumped into the wellbore.

DETAILED DESCRIPTION OF THE INVENTION

Reference is initially made to FIG. 1 a of the drawings whichillustrates an assembly, generally indicated by reference numeral 10,including first 20 and second 22 sand screens located on either side ofa tubular body 12, with a sleeve member 14, chamber 16 and port 18,according to an embodiment of the present invention.

Sand screens 20,22 are of any configuration known to those skilled inthe art. They are of generally cylindrical construction with multipleapertures passing therethrough in the form of a mesh, slots or holes.The aperture dimensions are selected to prevent the passage of sand intothe bore 24 of the assembly 10. A first end 26 of the first sand screen20 and a second end 28 of the second sand screen 22 are connected into atubular string 30 such as casing, liner or production tubing that isintended to be permanently set or completed in a well bore. The stringmay be a drill pipe or any other tubular string designed to be run in awell bore. A first end 32 of the second sand screen 22 and a second end34 of the first sand screen 20 are connected via a tubular body 12.

Tubular body 12 is a cylindrical tubular section having an innerdiameter preferably matching the inner diameter of the first 20 andsecond 22 sand screens. Body 12 includes a throughbore 36 which isco-linear with the throughbore 24 of the string 30.

A port 18 is provided through the side wall 38 of the body 12 to providea fluid passageway between the throughbore 36 and the outer surface 40of the body 12. While only a single port 18 is shown, it will beappreciated that a set of ports may be provided. These ports may beequidistantly spaced around the circumference of the body 12 and/or bearranged along the body to access the chamber 16.

In an embodiment, at the port 18 there is located a check valve 54. Thecheck valve 54 is a one-way valve which only permits fluid to pass fromthe throughbore 36 into the chamber 16. The check valve 54 can be madeto close when the pressure within the chamber 16 reaches a predeterminedlevel, this being defined as the morphed pressure value. Thus, when thepressure in the sleeve 14 reaches the morphed pressure value, the valve54 will close. Also arranged at the port 18 is a rupture disc 56. Therupture disc 56 is rated to a desired pressure at which fluid access tothe chamber is desired. In this way, the rupture disc 56 can be used tocontrol when the setting of the sleeve 14 is to begin. The disc 56 canbe operated by increasing pressure in the throughbore 36 with thepressure to rupture the disc being selected to be greater than the fluidpressure required to activate any other tools or functions in the wellbore.

Tubular body 12 is located coaxially within a sleeve member 14. Sleevemember 14 is a steel cylinder being formed from typically 316L or Alloy28 grade steel but could be any other suitable grade of steel or anyother metal material or any other suitable material which undergoeselastic and plastic deformation. Ideally the material exhibits highductility i.e. high strain before failure. The sleeve member 14 isappreciably thin-walled of lower gauge than the tubing body 12 and ispreferably formed from a softer and/or more ductile material than thatused for the tool body 12. The sleeve member 14 may be provided with anon-uniform outer surface 40 such as ribbed, grooved or other keyedsurface in order to increase the effectiveness of the seal created bythe sleeve member 14 when secured within another casing section orborehole 60.

Sleeve member 14 which surrounds the tubular body 12 is affixed theretovia welded or clamped connections 42, 44, respectively. Such attachments42, 44 are pressure-tight connectors. An O-ring seal (not shown) mayalso be provided between the inner surface 46 of the sleeve member 14and the outer surface 40 of the tubular body 12 to act as a secondaryseal or back-up to the seal provided by the welded connections. In anembodiment of the present invention, the first attachment means 42 isprovided by a mechanical clamp to fix the first end 48 of sleeve member14 to the tubular body 12. The second end 50 of the sleeve member 14 isconnected to the outer surface 40 of the tubular body 12 via a slidingseal arrangement. In this way, the second end 50 of the sleeve member 14can move longitudinally along the outer surface 40 of the tubular body12 while maintaining a seal between the surfaces to hold pressure withinthe chamber 16. This sliding seal is arranged so that the second end 50of the sleeve member 14 is permitted to move towards the first end 48.Thus when the sleeve member 14 is caused to move in a radially outwarddirection, during morphing, the sleeve contracts which causessimultaneous movement of the sliding seal. This has the advantage inreducing thinning of the material of the sleeve 14 by the radial outwardexpansion.

The attachments 42, 44 together with the inner surface 46 of the sleevemember 14 and the outward surface 40 of the body 12 define the chamber16. The port 18 is arranged to access the chamber 16 and permit fluidcommunication between the through-bore 24 and the chamber 16.

Thus, the assembly 10 is constructed by taking two sand screens 20,22,connecting them on either side of a tubular body 12 and locating asleeve member 14 over the tubular body 12. A first end 48 of the sleevemember 14 is attached to the tubular body 12 via the attachment 42 andthe second end 50 of the sleeve member 14 is also attached to thetubular body, via attachment 44. Assembly 10 is then connected into astring 30 as is known in the art and run into the wellbore 60. Theassembly 10 may be attached to the bottom of a casing or liner string.The assembly 10 is run into a position where a barrier is required andin the embodiment shown in FIG. 1 a, this is inside a wellbore 60between a first zone 62 and a second zone 64 of the formation 66.

When the assembly 10 is in position in the wellbore 60, a gravel slurry70 is pumped down the bore 24 of the string 30. This is illustrated inFIG. 1 b. The gravel 70 may be pumped directly through the bore 24 ormay be pumped through an inner string and gravel packing sub (not shown)used to deliver the gravel to the end 52 of the string 30 withoutdamaging the inner surface 58 of the string 30. The gravel 70 passes outof the end 52 of the string 30 and circulates up the annulus 68 betweenthe outer surface 40 of the body 12 and the inner surface 72 of thewellbore 60. The end 52 of the string 30 may be located in the rat-hole.This method of circulating the gravel 70 ensures that there are no voidsleft in the annulus 68. It also negates the requirement to installvalves, which may be referred to as shunt valves, in the tubing stringto inject gravel at points along the tubing string.

When the gravel 70 is in position in the annulus 68, pressure in thethrough-bore 36 of the body 12 is increased. This is typically fluidpressure delivered from a fluid delivery system inserted through thestring 30 as will be described with reference to FIG. 2 b. Pressure inthe through-bore 36 thus increases to a point where the disc 56 rupturesand allows fluid under pressure to pass through the check valve 54 atthe port 18. As detailed previously, multiple ports 18 may be locatedupon the tubular body 12 to increase the rate of fluid pressure enteringthe chamber 16. As the chamber 16 is cylindrical in nature and thematerial of the sleeve member 14 is more elastic than that of thetubular body 12, as pressure increases in the chamber 16, the sleevemember 14 will be forced radially outwardly from the tubular body acrossthe annulus 68 between the outer surface 40 of the tubular body 12 andthe inner surface 72 of the wellbore 60. This expansion of the sleevemember 14 by fluid pressure will initially force the gravel 70 out fromthe annulus 68 at the sleeve member 14 and then crush the gravel 70trapped between the sleeve member 14 and the inner surface 72. Thepressure will be sufficient to crush the gravel 70 into small particlessuch as a powder so that the morphed sleeve 14 creates a seal againstthe inner surface 72 of the wellbore 60. The crushed gravel 70 may formpart of this seal. This is illustrated in FIG. 1 c. This morphingprocess is known and operates by elastically and then plasticallydeforming the sleeve member 14. At a morphed fluid pressure value, thecheck valve 54 closes therefore sealing the chamber 16. The seal betweenthe assembly 10 and the inner surface 72 thus forms a barrier in thewellbore 60 so that fluid flow through the annulus 68 is prevented.Fluid flow from the formation 64 is then directed through the first sandscreen 20 for production from the lower, second zone 64 and through thesecond sand screen 22 for production from the upper, first zone 62. Eachzone 62,64 has therefore been completed with its own gravel pack 74,76respectively.

In an alternative embodiment, the sleeve member 14 may be expanded whilethe gravel 70 is still being pumped. When the sleeve member 14 has beenmorphed against the inner surface 72, a rupture disc 78 located on thesleeve member 14 towards the first end 48 is burst, allowing gravel 70to enter the chamber 16. This gravel 70 which enters the chamber 16 cansupport the sleeve member 14 in the morphed position and thereforeincrease the strength of the isolation barrier. The rupture disc 78 mayalternatively be in the form of a check valve, letting the gravel 70enter but not escape from the chamber 16.

Reference will now be made to FIG. 2 of the drawings which provides anillustration of a further method for completing a well according to anembodiment of the present invention. Like parts to those in the earlierFigures have been given the same reference numerals to aid clarity.

In use, the assembly 10 is conveyed into the borehole by any suitablemeans, such as incorporating the assembly 10 into a casing or linerstring 30 or on an end of a drill pipe and running the string into thewellbore 60 until it reaches the location within the open borehole 80 atwhich operation of the assembly 10 is intended. This location isnormally within the borehole at a position where the sleeve 14 a is tobe expanded in order to, for example, isolate the section of borehole 80b located above the sleeve 14 a from that below 80 d in order to providean isolation barrier between the zones 80 b, 80 d. Additionally afurther assembly 10 b can be run on the same string 76 so that zonalisolation can be performed in a zone 80 b.

The string 30 is run-in the wellbore 60 and hung from casing 82. Gravel70 is then pumped through the string 30 and exits at the end 52 where agravel packing sub 84 is located. The gravel slurry 70 fills the rathole 86 and travels up the annulus 68 between the outer surface 40 ofthe string 30 and the inner surface 72 of the wellbore 60. This is asillustrated in FIG. 2 a.

Reference is now made to FIG. 2 b which shows an activation fluiddelivery tool 88 run into the string 30. Tool 88 can be run into thestring 30 from surface by means of a coiled tubing 90 or other suitablemethod. The tool 88 is provided with upper and lower seal means 92,which are operable to radially expand to seal against the inner surface58 of the body 12 at a pair of spaced apart locations in order toisolate an internal portion of body 12 located between the seals 92; itshould be noted that said isolated portion includes the fluid port 18.Tool 88 is also provided with an aperture 96 in fluid communication withthe interior of the string 30.

To operate the tool 88, seal means 92 are actuated from the surface toisolate the portion of the tool body 12. Activation fluid is then pumpedunder pressure through the coiled tubing such that the pressurised fluidflows through tool aperture 96 and then via port 18 into chamber 16 andacts on the sleeve members 14 a,14 b in the same manner as describedhereinbefore. Use of such a tool allows setting of selective assemblies10 in a wellbore.

A detailed description of the operation of such a fluid delivery tool 88is described in GB2398312 in relation to the packer tool 112 shown inFIG. 27 of that patent with suitable modifications thereto, where theseal means 92 could be provided by suitably modified seal assemblies214, 215 of GB2398312, the disclosure of which is incorporated herein byreference. The entire disclosure of GB2398312 is incorporated herein byreference.

The increase in pressure of fluid causes the sleeve 14 a,14 b to moveradially outwardly crushing the gravel 70 and seal against a portion ofthe inner circumference of the borehole 80. The pressure within thechamber 16 continues to increase such that the sleeve 14 a,14 binitially experiences elastic expansion followed by plastic deformation.The sleeve 14 a,14 b expands radially outwardly beyond its yield point,undergoing plastic deformation until the sleeve 14 a,14 b morphs againstthe surface 72 of the borehole 80 as shown in FIG. 2 c. Accordingly, thesleeve 14 a,14 b has been plastically deformed and morphed by pressurefrom the chamber contents without any mechanical expansion means beingrequired. Note that gravel 70 is now separated into gravel packs 74, 76contained between barriers created by the sleeve members 14 a,14 b.

Fluid may be pumped into the chamber 16 at any desired pressure as thecheck valve 54 can be set to allow a calculated volume of fluid which issufficient to morph the sleeve to enter the chamber before closing. Whenclosed, the check-valve will trap any fluid remaining in the chamber 16.The pressure may be increased sufficiently to assist in crushing thegravel 70 and then bled-off before closing the port 18.

The sleeve 14 a,14 b will have taken up a fixed shape under plasticdeformation with an inner surface 46 matching the profile of the surface72 of the borehole 60 and the crushed gravel 70. An outer surface of thesleeve will also match the profile of the surface 72 of the borehole 60and the crushed gravel 70. A seal which effectively isolates the annulus94 of the borehole 80 above the sleeve 14 a from the annulus 98 belowthe sleeve 14 a is created. If two sleeves 14 a,14 b are set togetherthen zonal isolation can be achieved for the annulus 94 between thesleeves 14 a,14 b. At the same time the sleeves 14 a,14 b haveeffectively centered, secured and anchored the tubing string 30 to theborehole 60.

Also shown in FIG. 2 c is an inner completion string 100. The innercompletion string 100 includes spaced apart seals 102 to isolate therespective sand screens 62, 64 from each other. Valves 104 can then beopened sequentially for the selected production flow from each zone 80d, 80 b.

Reference will now be made to FIGS. 3 a-3 c of the drawings whichprovide an illustration of a further method for completing a wellaccording to an embodiment of the present invention. Like parts to thosein the earlier Figures have been given the same reference numerals toaid clarity.

Reference is initially made to FIG. 3 a which illustrates an assembly aspreviously described with reference to FIG. 1 a, generally indicated byreference numeral 10, including first 20 and second 22 sand screenslocated on either side of a tubular body 12, with a sleeve member 14,chamber 16 and port 18. The assembly of FIG. 3 a further comprises ashunt tubular assembly 110 which is arranged so as to run adjacent to,and in parallel with, tubular 12 traversing through sleeve member 14 asa discreet sealed continuous tubular member, according to an embodimentof the present invention.

The shunt tubular assembly 110 is shown as having a single shunt tubehowever it will be appreciated that several shunt tubes may be providedrunning in parallel to one another. The shunt tube 110 runs along theoutside of the sand screens 20, 22 and is a narrow bore tube constructedof a metal based material. The bore of the shunt tube 110 can be seen torun continuously through the sleeve 14 to allow the shunt tube 110 toflow continuously along the tubular 12. Dedicated crossover connectionsusing components (not shown) such as those known in the art would berequired between the sleeve 14 and shunt tube 110 to ensure a sealed andeffective crossover between components that allows the sleeve 14 tofunction effectively whilst continuous flow through the shunt tube 110is also possible.

In use, the assembly 10 is conveyed into the borehole by any suitablemeans, such as incorporating the assembly 10 into a casing or linerstring 30 or on an end of a drill pipe and running the string into thewellbore 60 until it reaches the location where the barrier is requiredand in the embodiment shown in FIG. 3 a, this is inside wellbore 60between a first zone 62 and a second zone 64 of the formation. Thislocation is within the borehole at the position where the sleeve 14 isto be expanded in order to, isolate the section of borehole 62 locatedabove the sleeve 14 from that below 64 in order to provide an isolationbarrier between the zones 62, 64.

When the sleeve 14 is in position in the annulus 68, pressure in thethrough-bore 36 of the body 12 is increased. This is typically fluidpressure delivered from a fluid delivery system inserted through thestring 30 as will be described with reference to FIG. 3 b. Pressure inthe through-bore 36 thus increases to a point where the disc 56 rupturesand allows fluid under pressure to pass through the check valve 54 atthe port 18. As detailed previously, multiple ports 18 may be locatedupon the tubular body 12 to increase the rate of fluid pressure enteringthe chamber 16. As the chamber 16 is cylindrical in nature and thematerial of the sleeve member 14 is more elastic than that of thetubular body 12, as pressure increases in the chamber 16, the sleevemember 14 will be forced radially outwardly from the tubular body acrossthe annulus 68 between the outer surface 40 of the tubular body 12 andthe inner surface 72 of the wellbore 60. The pressure will be sufficientthat the morphed sleeve 14 creates a seal against the inner surface 72of the wellbore 60. This is illustrated in FIG. 3 b. This morphingprocess is known and operates by elastically and then plasticallydeforming the sleeve member 14. At a morphed fluid pressure value, thecheck valve 54 closes therefore sealing the chamber 16. The seal betweenthe assembly 10 and the inner surface 72 thus forms a barrier in thewellbore 60 so that fluid flow through the annulus 68 is prevented. Notethat the shunt 112 is held against the tubular body 12 during themorphing process and is not moved radially outwards.

When the sleeve 14 is morphed in position in the wellbore 60, a gravelslurry 70 is pumped down the bore 111 of the shunt 112. This isillustrated in FIG. 3 c. The gravel 70 passes out of the shunt exits116, which may be a plurality of exit holes or slits as appropriate, andwhich are arranged beyond the morphed sleeve 14. The gravel 70 thencirculates around the annulus 68 between the outer surface 40 of thebody 12 and the inner surface 72 of the wellbore 60. This method ofcirculating the gravel 70 circulates locally to the morphed sleeve 14and ensures that there are no voids left in the annulus 68.

Once the gravel 70 has circulated the annulus 68 around the assembly 10the gravel 70 is allowed to set after which value 112 provided in theshunt 110 is closed thus sealing the shunt tube 110 completely. Thismethod of gravel provision ensures a complete annular barrier is formedaround the tubular 12 adjacent to the annular barrier of morphed seal 14without the morphed seal 14 being required to crush gravel during thesealing process.

In a further embodiment (not shown) gravel may be provided to annulus 68via shunt tube 110 and via string 30 such that it enters the annulus viashunt exits 112 and string end 52 enabling it to circulate up and roundthe annulus 68 as well as around sleeve 14 during installation. Such anarrangement would enable gravel 70 to circulated locally around thesleeve 14 as well as by means of circulation in the wellbore andsubsequent morphing of the sleeve 14 would act to crush gravel whichwould go on to form part of the annular seal around the assembly.

The principle advantage of the present invention is that it provides anexpandable completion system and method of completing a well in whichgravel packing for multiple completion zones can be easily achieved.

A further advantage of at least one embodiment of the present inventionis that it provides an expandable completion system and method ofcompleting a well in which gravel packing for multiple completion zonescan be achieved by circulation.

A still further advantage of at least one embodiment of the presentinvention is that it provides an expandable completion system and methodof completing a well in which selective isolation barriers can becreated along the length of the completion string after the gravel hasbeen pumped into the annulus.

It will be apparent to those skilled in the art that modifications maybe made to the invention herein described without departing from thescope thereof. For example, sliding sleeves may be incorporated on thetubular string to access the chambers and/or the sand screens.

1. A method of completing a well, comprising: locating a sleeve memberon the exterior of a tubular body and sealing it thereto to create achamber therebetween, using the tubular body to connect two sand screenstogether in an assembly; running the assembly on a string into awellbore and positioning the sleeve member at a position between zoneswithin a larger diameter structure; pumping fluid through a port in thetubular body to access the chamber; causing the sleeve member to moveradially outwardly to morph against an inner surface of the largerdiameter structure; and providing a gravel mixture through at least oneportion of the assembly to locate between the tubular body and thelarger diameter structure.
 2. A method according to claim 1 wherein themethod includes locating multiple assemblies on the string andundertaking the morphing of the sleeve and the provision of a gravelmixture at any desired locations where an isolation barrier is required.3. A method according to claim 1 wherein the method includes the step ofinserting an inner completion string into the string and isolating thesand screens by sealing between the inner completion string and thetubular body.
 4. A method according to claim 1 wherein the step ofproviding a gravel mixture includes pumping gravel slurry through thestring to exit at an end of the tubular body and circulate up an annulusbetween the assembly and the larger diameter structure.
 5. A methodaccording to claim 1 wherein the step of pumping of fluid through a portin the tubular body to access the chamber and cause the sleeve member tomove radially outwardly occurs after the gravel slurry is pumped throughthe string into the annulus.
 6. A method according to claim 5 whereinthe sleeve moves radially outwardly to crush the gravel and morphagainst the inner surface of the large diameter structure.
 7. A methodaccording to claim 1 wherein the method comprises causing the sleevemember to move radially outwardly to morph against an inner surface ofthe larger diameter structure before providing a gravel mixture bypumping gravel slurry through at least one shunt tubular component ofthe assembly to an exit located between the morphed sleeve member and anend of the tubular body such that the gravel slurry circulates around anannulus between the assembly and the larger diameter structure.
 8. Amethod according to claim 7 wherein the at least one shunt tubularcomponent is provided with a valve.
 9. A method according to claim 1wherein the step of providing a gravel mixture includes pumping gravelslurry through the string to exit at an end of the tubular body andcirculate up an annulus between the assembly and the larger diameterstructure and pumping gravel slurry through at least one shunt tubularcomponent of the assembly to an exit located between the sleeve memberand an end of the tubular body such that the gravel slurry circulatesaround an annulus between the assembly and the larger diameterstructure.
 10. A method according to claim 9 wherein the step of pumpingof fluid through a port in the tubular body to access the chamber andcause the sleeve member to move radially outwardly occurs after thegravel slurry is pumped into the annulus.
 11. A method according toclaim 10 wherein the sleeve moves radially outwardly to crush the graveland morph against the inner surface of the large diameter structure. 12.An expandable completion system, comprising: an assembly comprising twosand screens connected via a tubular body, the assembly includingconnections for location in a tubular string to be run in and securedwithin a larger diameter generally cylindrical structure; wherein asleeve member is positioned on the exterior of the tubular body, tocreate a chamber therebetween; the tubular body including a port topermit the flow of fluid into the chamber to cause the sleeve member tomove outwardly and morph against an inner surface of the larger diameterstructure wherein the assembly is operable to provide a gravel slurryinto an annulus between the assembly and the larger diameter structure.13. An expandable completion system according to claim 12 wherein thesleeve member has a first end which is affixed and sealed to the tubularbody and a second end which includes a sliding seal to permitlongitudinal movement of the second end over the tubular body.
 14. Anexpandable completion system according to claim 12 wherein the sandscreens are slotted liners.
 15. An expandable completion systemaccording to claim 12 wherein the system includes a plurality ofassemblies.
 16. An expandable completion system according to claim 15wherein the assemblies are separated by a tubular body, wherein a sleevemember is positioned on the exterior of the tubular body, to create achamber therebetween; the tubular body including a port to permit theflow of fluid into the chamber to cause the sleeve member to moveoutwardly and morph against an inner surface of the larger diameterstructure.
 17. An expandable completion system according to claim 12wherein the assembly(ies) comprises a string exit at an end.
 18. Anexpandable completion system according to claim 12 wherein theassembly(ies) comprises at least one shunt tubular having at least oneshunt exit located between the sleeve member and an end of the tubularbody.
 19. An expandable completion system according to claim 18 whereinthe at least one shunt tubular is provided with a valve.
 20. Anexpandable completion system according to claim 18 wherein the assemblycomprise string exit at an end and at least one shunt tubular having atleast one shunt exit located between the sleeve member and an end of thetubular body.